When Nancy King got a pet octopus, she made a serious commitment: She wouldn't spend a night away from her home in Dallas the entire time she had it. "I had decided it would be an experiment in whether I could have a relationship with an octopus," she says. "I sat with her every day and spent time with her, and I got rewarded for that."

Related News/Archive

Octopuses can be very interactive, and show evidence of a surprising degree of intelligence — even what seems like mischief-making.

King's Ollie demonstrated an ability to manipulate both objects and people by inventing a game. It made use of a glass-cleaning tool with two pieces held together by a magnet, one inside the tank and one outside.

"She learned that if she pulled off the inside of the cleaning magnet, the outside would drop off and we would come running," says King.

Denise Whatley of Atlanta teaches her octopuses that if they come to one corner of the tank, they'll get attention, and if they go to another spot, she'll take her hand out of the tank.

"I've had several of them do this off and on for two hours," she says. "With one, I would go sit down, and I wore myself out running back and forth — it was almost like it was laughing at me."

Whatley points out that octopuses have three hearts, a brain surrounding the esophagus, blue blood and no bones. Yet keepers say that individual octopuses have different personalities, and some say they can tell humans apart. "I had one little guy, I'd put my hand in the tank and he'd rub on my fingers to be petted," says Whatley. "But he would never do this for my husband, even though he's the one who feeds the animals."

The rewards of communing with these creatures come at a high price, though. This is an animal with specialized needs. For starters, it requires a lot of space. Whatley says an octopus needs at least a 55-gallon aquarium, with a second large tank for a sump to hold the complicated filtration equipment needed for a saltwater aquarium. Another backup tank setup is a good idea in case there's an emergency, like the octopus inking its tank, which can clog its gills and kill it.

And you'd better have a good lid, because the octopus is an escape artist.

All you can keep in the tank is one octopus, because they'll eat any tankmates, including other octopuses.

Feeding is complicated and expensive — you can't run out to the pet store for octopus chow. "There's no such thing," says King. "You go to Whole Foods and buy shrimp."

And that's the easy route — live food is superior both for nutrition and enrichment. "They profit from hunting a bit, and they do like it better," she says.

Kept properly, a suitable aquarium species will live its natural lifespan of no more than a couple of years.